-
Notifications
You must be signed in to change notification settings - Fork 0
/
render_tiles.py
executable file
·198 lines (164 loc) · 6.84 KB
/
render_tiles.py
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
#!/usr/bin/python
from math import pi,cos,sin,log,exp,atan
from subprocess import call
import sys, os
from Queue import Queue
import mapnik2
import threading
import argparse
custom_fonts_dir = '/Library/Fonts/'
mapnik2.register_fonts(custom_fonts_dir)
DEG_TO_RAD = pi/180
RAD_TO_DEG = 180/pi
# Default number of rendering threads to spawn, should be roughly equal to number of CPU cores available
NUM_THREADS = 4
def minmax (a,b,c):
a = max(a,b)
a = min(a,c)
return a
class GoogleProjection:
def __init__(self,levels=18):
self.Bc = []
self.Cc = []
self.zc = []
self.Ac = []
c = 256
for d in range(0,levels):
e = c/2;
self.Bc.append(c/360.0)
self.Cc.append(c/(2 * pi))
self.zc.append((e,e))
self.Ac.append(c)
c *= 2
def fromLLtoPixel(self,ll,zoom):
d = self.zc[zoom]
e = round(d[0] + ll[0] * self.Bc[zoom])
f = minmax(sin(DEG_TO_RAD * ll[1]),-0.9999,0.9999)
g = round(d[1] + 0.5*log((1+f)/(1-f))*-self.Cc[zoom])
return (e,g)
def fromPixelToLL(self,px,zoom):
e = self.zc[zoom]
f = (px[0] - e[0])/self.Bc[zoom]
g = (px[1] - e[1])/-self.Cc[zoom]
h = RAD_TO_DEG * ( 2 * atan(exp(g)) - 0.5 * pi)
return (f,h)
class RenderThread:
def __init__(self, tile_dir, mapfile, q, printLock, maxZoom):
self.tile_dir = tile_dir
self.q = q
self.m = mapnik2.Map(256, 256)
self.printLock = printLock
# Load style XML
mapnik2.load_map(self.m, mapfile, True)
# Obtain <Map> projection
self.prj = mapnik2.Projection(self.m.srs)
# Projects between tile pixel co-ordinates and LatLong (EPSG:4326)
self.tileproj = GoogleProjection(maxZoom+1)
def render_tile(self, tile_uri, x, y, z):
# Calculate pixel positions of bottom-left & top-right
p0 = (x * 256, (y + 1) * 256)
p1 = ((x + 1) * 256, y * 256)
# Convert to LatLong (EPSG:4326)
l0 = self.tileproj.fromPixelToLL(p0, z);
l1 = self.tileproj.fromPixelToLL(p1, z);
# Convert to map projection (e.g. mercator co-ords EPSG:900913)
c0 = self.prj.forward(mapnik2.Coord(l0[0],l0[1]))
c1 = self.prj.forward(mapnik2.Coord(l1[0],l1[1]))
# Bounding box for the tile
if hasattr(mapnik2,'mapnik_version') and mapnik2.mapnik_version() >= 800:
bbox = mapnik2.Box2d(c0.x,c0.y, c1.x,c1.y)
else:
bbox = mapnik2.Envelope(c0.x,c0.y, c1.x,c1.y)
render_size = 256
self.m.resize(render_size, render_size)
self.m.zoom_to_box(bbox)
self.m.buffer_size = 128
# Render image with default Agg renderer
im = mapnik2.Image(render_size, render_size)
mapnik2.render(self.m, im)
im.save(tile_uri, 'png256')
def loop(self):
while True:
#Fetch a tile from the queue and render it
r = self.q.get()
if (r == None):
self.q.task_done()
break
else:
(name, tile_uri, x, y, z) = r
exists= ""
if os.path.isfile(tile_uri):
exists= "exists"
else:
self.render_tile(tile_uri, x, y, z)
bytes=os.stat(tile_uri)[6]
empty= ''
if bytes == 103:
empty = " Empty Tile "
self.printLock.acquire()
print name, ":", z, x, y, exists, empty
self.printLock.release()
self.q.task_done()
def render_tiles(bbox, mapfile, tile_dir, minZoom=1,maxZoom=18, name="unknown", num_threads=NUM_THREADS):
print "render_tiles(",bbox, mapfile, tile_dir, minZoom, maxZoom, name,")"
# Launch rendering threads
queue = Queue(32)
printLock = threading.Lock()
renderers = {}
for i in range(num_threads):
renderer = RenderThread(tile_dir, mapfile, queue, printLock, maxZoom)
render_thread = threading.Thread(target=renderer.loop)
render_thread.start()
#print "Started render thread %s" % render_thread.getName()
renderers[i] = render_thread
if not os.path.isdir(tile_dir):
os.mkdir(tile_dir)
gprj = GoogleProjection(maxZoom+1)
ll0 = (bbox[0],bbox[3])
ll1 = (bbox[2],bbox[1])
for z in range(minZoom,maxZoom + 1):
px0 = gprj.fromLLtoPixel(ll0,z)
px1 = gprj.fromLLtoPixel(ll1,z)
# check if we have directories in place
zoom = "%s" % z
if not os.path.isdir(tile_dir + zoom):
os.mkdir(tile_dir + zoom)
for x in range(int(px0[0]/256.0),int(px1[0]/256.0)+1):
# Validate x co-ordinate
if (x < 0) or (x >= 2**z):
continue
# check if we have directories in place
str_x = "%s" % x
if not os.path.isdir(tile_dir + zoom + '/' + str_x):
os.mkdir(tile_dir + zoom + '/' + str_x)
for y in range(int(px0[1]/256.0),int(px1[1]/256.0)+1):
# Validate x co-ordinate
if (y < 0) or (y >= 2**z):
continue
str_y = "%s" % y
tile_uri = tile_dir + zoom + '/' + str_x + '/' + str_y + '.png'
# Submit tile to be rendered into the queue
t = (name, tile_uri, x, y, z)
queue.put(t)
# Signal render threads to exit by sending empty request to queue
for i in range(num_threads):
queue.put(None)
# wait for pending rendering jobs to complete
queue.join()
for i in range(num_threads):
renderers[i].join()
if __name__ == "__main__":
#python render_tiles.py tilemill/wards.xml mayor-2011/.tiles/wards/ -89.03 41.07 -87.51 42.50 9 16 2
parser = argparse.ArgumentParser(description='Render your tiles.')
parser.add_argument('style_file', help="File containing Mapnik styles")
parser.add_argument('tile_dir', help="Destination directory for rendered tiles")
parser.add_argument('lat_1', type=float, help="Top-left corner latitude")
parser.add_argument('lon_1', type=float, help="Top-left corner longitude")
parser.add_argument('lat_2', type=float, help="Bottom-right corner latitude")
parser.add_argument('lon_2', type=float, help="Bottom-right corner longitude")
parser.add_argument('min_zoom', help="Minimum zoom level to render", type=int, default="9")
parser.add_argument('max_zoom', help="Maximum zoom level to render", type=int, default="12")
parser.add_argument('cores', help="Number of rendering threads to spawn, should be roughly equal to number of CPU cores available", type=int, default="2")
args = parser.parse_args()
bbox = (args.lon_1, args.lat_2, args.lon_2, args.lat_1)
render_tiles(bbox, args.style_file, args.tile_dir, args.min_zoom, args.max_zoom)